Shares of Sears Holdings (SHLD) fall 7.5% - the most of any S&P 500 stock in early trading....

Shares of Sears Holdings (SHLD) fall 7.5% - the most of any S&P 500 stock in early trading. SA author Justin Weinstein says the stock is a risky play until the company successfully proves to consumers that it's able to turn around its fortunes.